Most human proteins are glycosylated. Increasing demand for recombinant glycosylated proteins of therapeutic and diagnostic importance has focused research on techniques for improving protein expression and controlling post-translational processing. We propose to use SUMO-fusion vector to improve protein expression and protein secretion and engineered humanized P.pastoris strain to control post-translational glycosylation. In Phase I, we will demonstrate that our novel system (i) is superior in increasing protein expression and secretion, facilitating protein purification and generating desired N-terminal amino acid, (ii) produce proteins with more than 90% homogeneity, (iii) produce proteins with mammalian-like N-glycan complex structures. As a proof-oF-principle we wi ll express and purify 10 cancer-related glycosylated proteins. Purified glycoproteins will be analyzed using DSA-FACE or mass spec to demonstrate mammalian-like post~translatjonal glycosylation. In Phase II we will use our developed system and establislled growth conditions to express, purify and characterize an additional 100 cancer-related glycoproteins. Our novel protein expression system not only improves protein expression/purification and controls post-translational glycosylation, but also reduces the time and cost of R&D, accelerating process from genomics to proteomics to therapeutic proteins.